#da{
    /*background-color: #00ee00;*/
    height: 720px;
    position: relative;
    padding-top: 5px;
}
#zuo{
    width: 10%;
    padding: 5px;
    height: 710px;
    /*background-color: #00a2d4;*/
    display: inline-block;
    position: absolute;
    top: 5px;
    left: 5px;
}
#you{
    margin-left: 172px;
    width: 90%;
    height: 710px;
    padding: 5px;
    /*background-color: red;*/
    display: inline-block;
}